| Message ID | 1360105784-12282-4-git-send-email-ks.giri@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 5 Feb 2013 15:09:43 -0800, Girish K S <girishks2000@gmail.com> wrote: > This patch adds support for spi controllers with > dedicated clk/miso/mosi/cs pins. It skips the gpio > parsing and initialization for controllers that > have dedicated pins. > > Signed-off-by: Girish K S <ks.giri@samsung.com> Instead of making this a quirk, you should use the presence/absense of a cs-gpios property to determin whether or not a gpio is used to manipulate the CS signal. Also, are you certain that you want to make this change? Most SPI controllers are actually unfriendly in that they insist on deasserting the CS line if the FIFO runs empty. Does this driver correctly keep the CS signal asserted when there are multiple transfers in a message? g. > --- > drivers/spi/spi-s3c64xx.c | 39 +++++++++++++++++++++++++++++++-------- > 1 file changed, 31 insertions(+), 8 deletions(-) > > diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c > index 90770bd..f06bbee 100644 > --- a/drivers/spi/spi-s3c64xx.c > +++ b/drivers/spi/spi-s3c64xx.c > @@ -36,6 +36,7 @@ > > #define MAX_SPI_PORTS 3 > #define S3C64XX_SPI_QUIRK_POLL (1 << 0) > +#define S3C64XX_SPI_QUIRK_GPIO (1 << 1) > > /* Registers and bit-fields */ > > @@ -404,14 +405,16 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, > if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ > /* Deselect the last toggled device */ > cs = sdd->tgl_spi->controller_data; > - gpio_set_value(cs->line, > - spi->mode & SPI_CS_HIGH ? 0 : 1); > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) > + gpio_set_value(cs->line, > + spi->mode & SPI_CS_HIGH ? 0 : 1); > } > sdd->tgl_spi = NULL; > } > > cs = spi->controller_data; > - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) > + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); > > /* Start the signals */ > writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); > @@ -503,7 +506,8 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, > if (sdd->tgl_spi == spi) > sdd->tgl_spi = NULL; > > - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) > + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); > > /* Quiese the signals */ > writel(S3C64XX_SPI_SLAVE_SIG_INACT, > @@ -842,7 +846,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( > return ERR_PTR(-ENOMEM); > } > > - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); > + /* In case of dedicated cs pin skip the gpio initialization */ > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) > + cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); > + > if (!gpio_is_valid(cs->line)) { > dev_err(&spi->dev, "chip select gpio is not specified or " > "invalid\n"); > @@ -883,7 +890,7 @@ static int s3c64xx_spi_setup(struct spi_device *spi) > return -ENODEV; > } > > - if (!spi_get_ctldata(spi)) { > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) { > err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH, > dev_name(&spi->dev)); > if (err) { > @@ -892,9 +899,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi) > cs->line, err); > goto err_gpio_req; > } > - spi_set_ctldata(spi, cs); > } > > + if (!spi_get_ctldata(spi)) > + spi_set_ctldata(spi, cs); > + > sci = sdd->cntrlr_info; > > spin_lock_irqsave(&sdd->lock, flags); > @@ -979,8 +988,11 @@ err_gpio_req: > static void s3c64xx_spi_cleanup(struct spi_device *spi) > { > struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi); > + struct s3c64xx_spi_driver_data *sdd; > + > + sdd = spi_master_get_devdata(spi->master); > > - if (cs) { > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) && cs) { > gpio_free(cs->line); > if (spi->dev.of_node) > kfree(cs); > @@ -1107,6 +1119,13 @@ static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd) > struct device *dev = &sdd->pdev->dev; > int idx, gpio, ret; > > + /* > + * If cs is not controlled by gpio, and > + * the SoC uses internal dedicated pins > + */ > + if (sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) > + return 0; > + > /* find gpios for mosi, miso and clock lines */ > for (idx = 0; idx < 3; idx++) { > gpio = of_get_gpio(dev->of_node, idx); > @@ -1133,6 +1152,10 @@ free_gpio: > static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd) > { > unsigned int idx; > + > + if (sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) > + return; > + > for (idx = 0; idx < 3; idx++) > gpio_free(sdd->gpios[idx]); > } > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
On Wed, Feb 6, 2013 at 2:40 AM, Grant Likely <grant.likely@secretlab.ca> wrote: > On Tue, 5 Feb 2013 15:09:43 -0800, Girish K S <girishks2000@gmail.com> wrote: >> This patch adds support for spi controllers with >> dedicated clk/miso/mosi/cs pins. It skips the gpio >> parsing and initialization for controllers that >> have dedicated pins. >> >> Signed-off-by: Girish K S <ks.giri@samsung.com> > > Instead of making this a quirk, you should use the presence/absense of a > cs-gpios property to determin whether or not a gpio is used to > manipulate the CS signal. I can do this for CS signal. Other signals are also dedicated pins. can i check the "gpios" property for them? > > Also, are you certain that you want to make this change? Most SPI > controllers are actually unfriendly in that they insist on deasserting the > CS line if the FIFO runs empty. Does this driver correctly keep the CS > signal asserted when there are multiple transfers in a message? The CS signal is asserted when the slave select bit is cleared, this is done in the enable_cs function. The CS signal is deasserted when the slave select bit is set, this is done in the disable_cs function. enable_cs is called at the begining of the message transfer and disable is called at the end of the transfer. > > g. > >> --- >> drivers/spi/spi-s3c64xx.c | 39 +++++++++++++++++++++++++++++++-------- >> 1 file changed, 31 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c >> index 90770bd..f06bbee 100644 >> --- a/drivers/spi/spi-s3c64xx.c >> +++ b/drivers/spi/spi-s3c64xx.c >> @@ -36,6 +36,7 @@ >> >> #define MAX_SPI_PORTS 3 >> #define S3C64XX_SPI_QUIRK_POLL (1 << 0) >> +#define S3C64XX_SPI_QUIRK_GPIO (1 << 1) >> >> /* Registers and bit-fields */ >> >> @@ -404,14 +405,16 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, >> if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ >> /* Deselect the last toggled device */ >> cs = sdd->tgl_spi->controller_data; >> - gpio_set_value(cs->line, >> - spi->mode & SPI_CS_HIGH ? 0 : 1); >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) >> + gpio_set_value(cs->line, >> + spi->mode & SPI_CS_HIGH ? 0 : 1); >> } >> sdd->tgl_spi = NULL; >> } >> >> cs = spi->controller_data; >> - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) >> + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); >> >> /* Start the signals */ >> writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); >> @@ -503,7 +506,8 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, >> if (sdd->tgl_spi == spi) >> sdd->tgl_spi = NULL; >> >> - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) >> + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); >> >> /* Quiese the signals */ >> writel(S3C64XX_SPI_SLAVE_SIG_INACT, >> @@ -842,7 +846,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( >> return ERR_PTR(-ENOMEM); >> } >> >> - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); >> + /* In case of dedicated cs pin skip the gpio initialization */ >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) >> + cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); >> + >> if (!gpio_is_valid(cs->line)) { >> dev_err(&spi->dev, "chip select gpio is not specified or " >> "invalid\n"); >> @@ -883,7 +890,7 @@ static int s3c64xx_spi_setup(struct spi_device *spi) >> return -ENODEV; >> } >> >> - if (!spi_get_ctldata(spi)) { >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) { >> err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH, >> dev_name(&spi->dev)); >> if (err) { >> @@ -892,9 +899,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi) >> cs->line, err); >> goto err_gpio_req; >> } >> - spi_set_ctldata(spi, cs); >> } >> >> + if (!spi_get_ctldata(spi)) >> + spi_set_ctldata(spi, cs); >> + >> sci = sdd->cntrlr_info; >> >> spin_lock_irqsave(&sdd->lock, flags); >> @@ -979,8 +988,11 @@ err_gpio_req: >> static void s3c64xx_spi_cleanup(struct spi_device *spi) >> { >> struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi); >> + struct s3c64xx_spi_driver_data *sdd; >> + >> + sdd = spi_master_get_devdata(spi->master); >> >> - if (cs) { >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) && cs) { >> gpio_free(cs->line); >> if (spi->dev.of_node) >> kfree(cs); >> @@ -1107,6 +1119,13 @@ static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd) >> struct device *dev = &sdd->pdev->dev; >> int idx, gpio, ret; >> >> + /* >> + * If cs is not controlled by gpio, and >> + * the SoC uses internal dedicated pins >> + */ >> + if (sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) >> + return 0; >> + >> /* find gpios for mosi, miso and clock lines */ >> for (idx = 0; idx < 3; idx++) { >> gpio = of_get_gpio(dev->of_node, idx); >> @@ -1133,6 +1152,10 @@ free_gpio: >> static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd) >> { >> unsigned int idx; >> + >> + if (sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) >> + return; >> + >> for (idx = 0; idx < 3; idx++) >> gpio_free(sdd->gpios[idx]); >> } >> -- >> 1.7.10.4 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > > -- > Grant Likely, B.Sc, P.Eng. > Secret Lab Technologies, Ltd.
On Tue, Feb 05, 2013 at 03:09:43PM -0800, Girish K S wrote: > This patch adds support for spi controllers with > dedicated clk/miso/mosi/cs pins. It skips the gpio > parsing and initialization for controllers that > have dedicated pins. > if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ > /* Deselect the last toggled device */ > cs = sdd->tgl_spi->controller_data; > - gpio_set_value(cs->line, > - spi->mode & SPI_CS_HIGH ? 0 : 1); > + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) > + gpio_set_value(cs->line, > + spi->mode & SPI_CS_HIGH ? 0 : 1); > } This isn't going to work with system designs which ignore the /CS line the controller has and just use a GPIO instead. This is very common, for example when connecting multiple devices to the same SPI bus. It seems like there's really two changes here. One change is making the provision of pinmux information optional, the other is allowing the user to use the controller /CS management rather than using GPIO.
On Thu, Feb 7, 2013 at 3:55 AM, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote: > On Tue, Feb 05, 2013 at 03:09:43PM -0800, Girish K S wrote: >> This patch adds support for spi controllers with >> dedicated clk/miso/mosi/cs pins. It skips the gpio >> parsing and initialization for controllers that >> have dedicated pins. > >> if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ >> /* Deselect the last toggled device */ >> cs = sdd->tgl_spi->controller_data; >> - gpio_set_value(cs->line, >> - spi->mode & SPI_CS_HIGH ? 0 : 1); >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) >> + gpio_set_value(cs->line, >> + spi->mode & SPI_CS_HIGH ? 0 : 1); >> } > > This isn't going to work with system designs which ignore the /CS line > the controller has and just use a GPIO instead. This is very common, > for example when connecting multiple devices to the same SPI bus. As per grant's comment i would remove the quirk option and check for "cs-gpio" property to handle /CS. When multiple devices are connected to the same spi bus, "cs-gpio" entry would exist in the dts file, and works with /CS gpio lines. > > It seems like there's really two changes here. One change is making the > provision of pinmux information optional, the other is allowing the user > to use the controller /CS management rather than using GPIO. As suggested i would make two changes. 1. would parse the "gpios" property and make decision whether to use gpios/dedicated pins for miso/miso/clk. 2.would parse "cs-gpio" property from dts node to handle the chip select correct me if my understanding is wrong
On Thu, Feb 07, 2013 at 10:54:01AM -0800, Girish KS wrote: > As suggested i would make two changes. > 1. would parse the "gpios" property and make decision whether to use > gpios/dedicated pins for miso/miso/clk. > 2.would parse "cs-gpio" property from dts node to handle the chip select > correct me if my understanding is wrong I think that's probably OK.
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 90770bd..f06bbee 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -36,6 +36,7 @@ #define MAX_SPI_PORTS 3 #define S3C64XX_SPI_QUIRK_POLL (1 << 0) +#define S3C64XX_SPI_QUIRK_GPIO (1 << 1) /* Registers and bit-fields */ @@ -404,14 +405,16 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ /* Deselect the last toggled device */ cs = sdd->tgl_spi->controller_data; - gpio_set_value(cs->line, - spi->mode & SPI_CS_HIGH ? 0 : 1); + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) + gpio_set_value(cs->line, + spi->mode & SPI_CS_HIGH ? 0 : 1); } sdd->tgl_spi = NULL; } cs = spi->controller_data; - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); /* Start the signals */ writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); @@ -503,7 +506,8 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, if (sdd->tgl_spi == spi) sdd->tgl_spi = NULL; - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); /* Quiese the signals */ writel(S3C64XX_SPI_SLAVE_SIG_INACT, @@ -842,7 +846,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( return ERR_PTR(-ENOMEM); } - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + /* In case of dedicated cs pin skip the gpio initialization */ + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) + cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + if (!gpio_is_valid(cs->line)) { dev_err(&spi->dev, "chip select gpio is not specified or " "invalid\n"); @@ -883,7 +890,7 @@ static int s3c64xx_spi_setup(struct spi_device *spi) return -ENODEV; } - if (!spi_get_ctldata(spi)) { + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) { err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH, dev_name(&spi->dev)); if (err) { @@ -892,9 +899,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi) cs->line, err); goto err_gpio_req; } - spi_set_ctldata(spi, cs); } + if (!spi_get_ctldata(spi)) + spi_set_ctldata(spi, cs); + sci = sdd->cntrlr_info; spin_lock_irqsave(&sdd->lock, flags); @@ -979,8 +988,11 @@ err_gpio_req: static void s3c64xx_spi_cleanup(struct spi_device *spi) { struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi); + struct s3c64xx_spi_driver_data *sdd; + + sdd = spi_master_get_devdata(spi->master); - if (cs) { + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) && cs) { gpio_free(cs->line); if (spi->dev.of_node) kfree(cs); @@ -1107,6 +1119,13 @@ static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd) struct device *dev = &sdd->pdev->dev; int idx, gpio, ret; + /* + * If cs is not controlled by gpio, and + * the SoC uses internal dedicated pins + */ + if (sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) + return 0; + /* find gpios for mosi, miso and clock lines */ for (idx = 0; idx < 3; idx++) { gpio = of_get_gpio(dev->of_node, idx); @@ -1133,6 +1152,10 @@ free_gpio: static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd) { unsigned int idx; + + if (sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO) + return; + for (idx = 0; idx < 3; idx++) gpio_free(sdd->gpios[idx]); }
This patch adds support for spi controllers with dedicated clk/miso/mosi/cs pins. It skips the gpio parsing and initialization for controllers that have dedicated pins. Signed-off-by: Girish K S <ks.giri@samsung.com> --- drivers/spi/spi-s3c64xx.c | 39 +++++++++++++++++++++++++++++++-------- 1 file changed, 31 insertions(+), 8 deletions(-)